Fuzzy-based approach for power smoothing of a full-converter wind turbine generator using a supercapacitor energy storage

Wind turbine generators (WTGs) are one of the fastest growing renewable energy source technologies. Due to the nature of wind, power fluctuations of WTGs can cause significant problems in the distribution network. In this study a fuzzy-based approach is proposed for a full-converter WTG coupled with a supercapacitor energy storage system. The fuzzy system is designed to smooth out the wind power fluctuations and also maintain an energy reserve of the supercapacitor for short-term grid disturbances. The fuzzy approach is thoroughly tested and compared with a conventional power smoothing technique and with the case without an energy storage system (ESS). Closed-loop digital simulations showed that the proposed fuzzy scheme enhances wind power smoothing and properly manages the state of charge (SOC) of the supercapacitor during faults in the simulated microgrid. Having less power fluctuations and the availability of the ESS to comply with the low-voltage ride through (LVRT) requirement, the WTG and the microgrid operation were considerably improved.